Indexed as a schematic, the 44.5 KB PDF named 2SD1328_E should be a datasheet for the 2SD1328, which the JIS 2SD prefix identifies as an NPN bipolar transistor for low-frequency service. The _E suffix possibly indicates an English-language release, not confirmed by the name. A technician uses such a sheet to locate base, collector and emitter, verify voltage and power limits and pick a substitute. Match the package and marking on the actual part first, as the name lists neither maker nor case.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.